nuttyd

Hi everyone, I am building a 50" Sport Fisher and would like to make this one R/C. I would like to have reverse on this also.
I would greatly appreciate any help choosing moters, props, shafts, remote, well pretty much everything.
Also do I need to reverse one engine?
Thanks
Duane

Rich404

Hi Duane,

If you ask 10 different people you are going to get 10 different answers on the subject. It has a lot to do with budget when it comes to boats. Some people like the cheap stuff whereas others are into quality. I personally believe that if you get the cheap stuff you are going to replace it sooner than later.... Also you don't wan't to wave goodbye to your boat because some cheap but critical component failed far offshore...but that's just one opinion..

A 50" sportfisher should have the ability to plane therefore you would want powerful motors that will be in the 10,000RPM range. Because the boat is scale the ESC should have reversing capabilities but you will a difficult time doing this if the motors are gas/glo etc. I would go electric and save the hassle.

If I was going to run a 50" sportfisher this is what I would do:

(2) Astroflight 25's or 40's. electric motors

(2) MACK marine stuffing tubes/shafts 18-24"

(2) Mack marine rudders

(1-2) astroflight or any decent reversing ESC's depending if you want independant throttles..

(2) 3 blade 1.75" props to run the motors direct

(2) 12V batteries NIMH 5000MAH or greater

Radio with receiver (I like the Robbe F-14 marine but Futaba or Hitec are good too. As long as it has good range choice is yours....

Then little stuff like:

Watercooling accesories and motor-shaft couplers.

I hope this gives you ideas.

A while back there were some guys that were talking about the Dumas Donzi Z 65 that is 49". Here was there take on the subject:

www.rcuniverse.com/forum/m_8797788/anchors_8798429/mpage_1/key_/anchor/tm.htm

Good luck and post pics.

-Rich.

mfr02

2nd of the ten different answers.

buzrow4

Chris craft feaver no cure....

nuttyd

Rich and MFR,
You both bring up some good points and options to consider, now I did stick a couple 540's in in it with reversing esc's and 2 blade props already.
NOW, I did not put this setup in the sport fisher I put it in  52" yacht of my own design to get an Idea of what I'm up against.
This is subject to change on the first shake down, the lakes have been froze around here but starting to break up so hopefully soon I can do it.
I'm going rc on a couple other boats also and I'm looking into the options Rich said and I like the sounds of them also. If I'd seen that post before I bought this stuff, I would have went that direction as i was wanting to keep everything 12 volt.
Well I'm off to see if theres an opening to run this thing, if so I'll post a video.

Buzrow,
 The  scale sports fisher is an Ocean 50 Convertable SS, not quite complete yet but will be soon. It's wood and rather heavy as most scale boats are to keep the water line right. Im at 32lb's right now and can add weight or take out a little if needed.
The yacht I'm testing now is around the same weight.

Captain Action

Good day Boaters
For a ESC for a two motor drive boat I would like to recommend the Sabertooth dual motor controler by Demension engineering. I have used them in a few RC projects and must say
that thay are vary good units and well priced. They have a few models, depending on your power needs.
Good luck

yjguy

As opposed to the 540 motors, i have used a set of 800 sized motors with excellent results. the torque is amazing and are really efficient. I also run gear reductions off the motors aswell. The gear reduction will allow for more efficient power. My first plan of attack is usually find the most scale correct propeller and work backwards to the motor gearing. A quick bit of math will find your proper gear ratio with the motor voltage, RPM, propeller operating range, and the planned speed for the model.

as a hint, I am piecing together power for a new project. Twin 800 motors, (aprox 18000RPMs@12v) 5.0:1 reductions with 3 1/2" 5 blade props. The hull LOA is 75" with a 23 beam, I am expecting it to weigh in at close to 100lbs when ready to run. I will have removable ballast. this is not a boat I am looking to break any speed records, its a full displacement pleasure boat.

Tom

Rich404

Hi Tom,

When you get started be sure to set up a build log on this site!

-Rich.

mfr02

Having now seen the weight, I go along with vjguy.  800 or 900 size motors for the grunt needed for performance.

nuttyd

Do you have a link for them motors and gear reduction system? Or do you build the gear reduction?

Rich404

Hi Nuttyd,

I would still choose the Astroflight motors over 540, 800 or even 900 motors. The Astroflight motors are powerful and efficient. www.astroflight.com/index.php

There are a bunch of ways to go about gear reduction. Some ways are loud and other ways are quiet and smooth. Before spending the money on gear reduction try running the boat direct first and see how it goes. If the motor gets hot quickly try smaller props until the motor is happy.

If you still decideto go with gear reduction use a 2:1 ratio then try larger props to increase performance. Anything greater than 2:1 will stifle performance and your boat will move like a tug boat. If gears like the brass metal gears that Dumas sellsare used, theboat will sound like a blender cruising across the water because of the metal on metal action. If a pulley is used and there is one on the motor and one on the shaft coupled by a belt the system will be much quieter.

Here is a place online that custom makes belt drives and everything you need tocreate a quiet gear reduction system for your boat if you decide to go that route.. www.sdp-si.com/

-Rich.

nuttyd

Rich
Aw man now I'm getting somewhere with those two links you sent, all of my searching has lead to just cheap kids stuff. If theres any other links you can think of for this build please share. Been trying to find a micro motor and reduction to run the radars also.

Rich404

Hi Duane,

Kid stuff makes me cringe...especially when you spend a long time building something that you want to be proud of...

As for the rotating radar you can do 2 things. Some people open up servos and remove the motor or you can just buy a cheap mini motor. The choice is yours..

Here is another useful link that will enable you to find a mini motor. Also this site has some other pretty useful "stuff". www.allelectronics.com/make-a-store/category/400/Motors/1.html

-Rich.

nuttyd

Good info Rich,
Another thing, What is a good stuffing box and shaft to use?

Rich404

Hi Nutty'd,

Use M.A.C.K. marine for brass stuffing box, stainless steel shaft, and rudder. I am using 3/16" in a Dauntless. It is on the bottom of the page. They also have propellers as well.

www.mackproductsrc.com/props_&_hardware.htm

-Rich.

Rich404

you need shaft struts too...they are on the same page...

-R.

Rich404

Rich404

Oh yes and one more thing...

Both model boats and full sized boats are governed by the "hole in the water rule"...There is no escaping pouring lots of money into them..

-Rich.

nuttyd

As I said before I put a couple 550's in another boat to see what would happen, its about the same size and weight. It did'nt do to good, I'm not trying to break any speed record but getting up on plane would be nice as I'm going to go ahead and keep this stuff in this boat even though its not top notch stuff. The boat I'm wanting to actually do RC for me is going to be the good stuff.

There are two Traxxas Titan 12T 550's, and two Traxxas props R and L turn. The motors are set up to turn R and L.
Right hand starboard and Left hand port.
The props i think are the problem here, 2" and not sure about the pitch but the motors do not get up to speed at all.

Any idea's what I could do with this boat just to get it moving a little, It's more for my son to play with.

nuttyd

Rich404

Hi Nuttyd,

Beforeanyone can diagnose or make suggestionswe need to know a few more things about the boat and the motor.

1) how long is the boat?

2) How wide is the boat

3) how heavy is the boat? (Especially with batteries and ready to sail)

4) What type of hull is it?

5) How many RPM's are the motor?

6) What sizeis the motor can? (Length/width/height)

(7) what voltage and MAH are the batteries are bieng used.

BTW: That's cool that you run boats with your son. I can't wait until my boy is old enough to run them.

-Rich.

rblubaugh

My Feedback: (5)

Maybe it's just the picture but the motors so not look to be aligned with the drive shaft? Maybe they are all right but there can be a loss of power there if they are very far off. Try the smaller props first and if possible realign the motors by making the base mounting holes over size in the motor mount base so the whole thing can be moved around (left or right). If necessary, you can shim up the whole mount to bring it into alignment vertically.

The better the alignment the better the motors will perform.

Next I would try 1 3/4" props; you could be loading down the motors thus reducing the RPMs of those 12T Titan 550's.

Bob

rblubaugh

My Feedback: (5)

Yeh, try that.

yjguy

I built a Dumas Donzi Z65 a few years ago. I ran 800 sized motors on a gear reduction units (turbo trans from FinedesignRC.com) with a 3:1 reduction. That was a nice set up but the gear reductions were pricey. My current scale boat that I have been working on is a Modelslipoways Broom 44. I made my own motor mounts and belt drive reductions from home depot purchased fiberglass bathroom board. I doubled it up with using thick CA and weights. I mapped out my motor and shaft areas. I "milled" everything out by hand with a dremel. That stuff is really strong and its easy to work with a dremel. I do not have pics of wither boat currently, I sold the Donzi, and the Broom 44 is packed up and I havent louched it for a while now. I will be selling it soon for to fund the BIG DOG! I found a local guy that is trying to produce an 1/12th kit of the Nordhavn EYF 75. His molds are about complete and its about to start producing them. If anyone is interested in one, let me know and I can get specs, pics price and lead time. I have seen almost every plug and mold that he has made for this project. I have also seen the model in person. I must say it is a amazing boat. I will have some pics this week

Tom

yjguy

Mcmastercarr.com is an awesome place to find belt drive, gears, shafts bearing etc. They are an industrial supplier but will sell to anyone with a credit card. the online store is a bit tricky to work at first but you get used to it.

Tom